Exam 13: Population Dynamics Over Space and Time

The females of a certain species of fish produce on average 1000 eggs each year. By chance some females produce a few more eggs than average, and others produce a slightly fewer eggs than average. This is an example of

Consider the time series of population sizes in years 1 and 2 for populations a, b, c, and

Which contributed to the decline and extinction of black-footed ferrets? I. Habitat destruction reduced carrying capacity of ferrets. II. Lethal diseases like canine distemper killed many ferrets. III. Increasingly fragmented ferret populations were more likely to go extinct.

Which conclusion does the figure support?

In the logistic model with delayed density dependence, an increase in the length of the time delay will affect population dynamics by

A species of grass is affected by the amount of rainfall in the spring. In years of high rain, the grass survives better than in years of low rain. This is an example of

Explain the biological reason that higher intrinsic growth rates and longer delays lead to greater oscillations in population size.

Variation in birth and death rates due to random differences among individuals is

Consider these two populations, which exhibit variation in population size over time. In which population is the fluctuation most likely due to environmental variation, and in which population is fluctuation most likely due to density dependence? Explain your answer.

Which is TRUE about dampened oscillations? I. They are a pattern of population growth in which a population continues to exhibit large oscillations over time. II. They are a form of demographic stochasticity. III. They are expected to occur when rτ = 1.

Define the three components of the basic model of metapopulation dynamics, = (1 − e/c). Explain one way conservation biologists can affect each of the variables e and c to protect a species.

Which is an example of a metapopulation? I. Insects live in isolated patches of forest surrounded by agriculture. Sometimes the population in a patch goes extinct, but eventually the insects recolonize that patch. II. A species of bird is found in Canada during the summer. In the fall, the species migrates to the Caribbean and spends the winter there. In the spring it returns to Canada. III. A species of fish lives in a fast-flowing cold river. A dam is constructed on the river, causing the fish to go extinct because of warmer water.

Under the basic model of metapopulation dynamics, when the extinction rate is equal to the colonization rate, we predict that the proportion of patches occupied ( ) will equal

Use the following figure to answers questions 16 to 18: -Which panel illustrates a population growing under a logistic model with time delays of 2 years, intrinsic rate of population increase of 0.5, and carrying capacity of 250 individuals?

Consider a logistic model that includes a time delay in density dependence and exhibits dampened oscillations. If the carrying capacity is increased but all other parameters remain the same, which of the following outcomes is most likely?

Which correctly describes metapopulations? I. They can arise from habitat fragmentation. II. The frequency of occupied habitats is due to the balance of extinction and colonization. III. The basic metapopulation model assumes that all patches are equal in quality.

Which of the following contributed to the success of conservation programs that reintroduced ferrets to the wild?

Consider a logistic model that includes a time delay in density dependence and exhibits dampened oscillations. If the intrinsic rate of increase is reduced but all other parameters remain the same, which of the following outcomes is most likely?

Two species of mice are similar in many characteristics. However, species A has large fat reserves that increase survival over periods when environmental resources are depleted, while species B has no fat reserves. Which species is more likely to exhibit oscillating population dynamics? Explain your answer.

In population dynamics following the logistic model, an overshoot occurs when